Study of mechanisms of hyperlipoproteinemia in animal models will be continued. These models will include the rats with streptozotocin induced diabetes fed high cholesterol diets, Zucker fatty rats, rats with hyperinsulinemia induced by implantation of pancreatic islet cells, and rats with experimental nephrosis. Studies on the Zucker rat will focus on the mechanism of induction of fatty livers by diet. It is also proposed to utilize preparative isoelectric focusing to separate lipoprotein subclasses. These subclasses will be characterized in terms of their chemical and physical properties. This technique will also be used to separate and study apoproteins which exist in polymorphic forms such as apo E and apo A-11.